This invention relates to the binding of a metal, capable of forming a metal hydride, to a surface.
My copending U.S. patent application Ser. No. 695,073, filed Jan. 25, 1985 now U.S. Pat. No. 4,599,867 entitled "Hydrogen Storage Cell" describes a means of storing hydrogen in the form of a metal hydride. The disclosure of the cited application is incorporated by reference herein.
In the structure disclosed in the cited application, the hydride is coated onto the surface of a plurality of metal fins which are attached to heat transfer tubes. The fins are closely spaced, so that the weight of hydrogen stored per unit volume is high, approaching one pound per cubic foot. Because the formation of a metal hydride is quite exothermic, the rate of addition of removal of hydrogen from the cell is limited by the ability of the cell to conduct heat to or from the hydride. The cell disclosed in the cited application provides for rapid heat transfer so that the cell can be used in a heat pump, a hydrogen compressor, or to store hydrogen fuel for a vehicle.
Practical problems are encountered in coating the hydride-forming material onto the working surface. When a metal absorbs hydrogen to form a hydride, the metal expands and evolves heat. When the hydride evolves hydrogen and reverts to the metal, it contracts and absorbs heat. Thus, the binder used to hold the hydride-forming metal to its surface must be elastic, permeable to hydrogen, and must be heat stable. The present invention discloses a method for coating the hydride onto a solid support surface, and disclosed compositions which can be used as binders.